-LRB- CNN -RRB- A leader of pro-Russian rebels in eastern Ukraine 's Donetsk region said Friday he is not interested in a truce with the Ukrainian government in Kiev because his troops are on the offensive .

`` Since we 're attacking , there is no sense to have peace talks now , '' Aleksandr Zakharchenko , leader of the self-proclaimed People 's Republic of Donetsk , said in a meeting with university students , according to his media office .

`` We 've made this mistake before . It 's not decent to repeat it , '' he said .

Thousands have been killed in months of conflict between the rebels and Ukrainian troops , and a ceasefire agreed to in September crumbled long ago . Zakharchenko 's comments came two days after the foreign ministers of Ukraine and Russia met in Berlin to discuss a way out of the violence .

But Zakharchenko showed no interest in the talks .

`` There will be no attempts from our side to talk about the ceasefire , '' he said , reported Russian state news agency RIA . `` We will be on the offensive until we reach the border of Donetsk region . ''

He said that he was interested in cooperating with Ukraine on prisoner exchanges . `` We need to get our guys who 've been captured , '' he said , according to RIA .

Despite the talks in Berlin , violence in the breakaway Donetsk and Luhansk regions in eastern Ukraine shows no signs of abating .

Power is out in and around Luhansk after militants shelled a power plant there , Luhansk regional official Hennady Moskal told Ukraine 's state-run Ukrinform news agency . Moskal noted that the local water supply and boilers are off , and trolley buses are n't operating .

Thursday 's shelling of a transit stop in Donetsk city -- an attack that Ukraine 's Defense Ministry blamed on rebels -- killed eight civilians , according to state news reports . But Ukrainian troops have come under heavy fire , as well .

That includes 115 attacks in a recent 24-hour period that killed three troops and wounded 50 more , Ukrinform reported Friday .

The news agency said that `` Russian-terrorist troops '' faced off with Ukrainian soldiers Thursday along Bakhumtka Highway , even posting a picture that showed a man with stripes on his clothing , suggesting that he was part of the Russian military .

This is in line with Kiev 's repeated assertions that Russia has not only actively supported rebels with arms , but has sent its own troops across the border to battle Ukrainian forces . On Wednesday , for instance , Ukrainian President Petro Poroshenko said that `` more than 9,000 Russian troops -LRB- crossed -RRB- our Russian-Ukrainian border , bring with them hundreds and hundreds of tanks , armed personnel carriers , and killing Ukrainian civilians and attacking Ukrainian troops . ''

Claims that Russian forces entered Ukraine ` complete rubbish , ' Russia says

Russian Foreign Minister Sergey Lavrov promptly responded to this assertion with a firm denial , much like other denials made by Russian officials in recent months over similar allegations of armed intervention .

`` As to the flow of troops and armaments , this is not the first time we hear something like that , '' he said . `` And each time I hear that , I say if you 're so confident about that , please present us with facts , but no one has been able to provide us with these facts . ''

Russian forces , equipment enter Ukraine , PM says

Pro-Russian separatists have claimed control of parts of eastern Ukraine since the spring of 2014 , despite a push by Ukrainian forces to defeat them . From mid-April to January 21 , the conflict had killed at least 5,086 people and injured at least 10,948 others , said the United Nations .

`` We fear that the real figure may be considerably higher , '' the Office of the U.N. High Commissioner for Human Rights said about the death toll in a report released Friday .

At least 262 people were killed in the fighting from January 13 through Wednesday alone , the report said .

Unrest in Ukraine began with protests in the country 's capital last year after President Viktor Yanukovych , favoring closer ties to Russia , dropped plans to sign a political and economic agreement with the European Union .

After months of protests and days of deadly clashes between demonstrators and security personnel in Kiev , Parliament ousted Yanukovych in February . Weeks later , Russia annexed the Crimean Peninsula .

Then in April , violence broke out in two Ukrainian regions that border Russia -- Donetsk and Luhansk -- as separatist leaders declared independence from the government in Kiev .

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Aleksandr Zakharchenko : No sense in talking peace since we 're on the offensive

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Zakharchenko is the leader of rebels in eastern Ukraine 's Donetsk region

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He says he still wants prisoner exchanges